Railroad switch heaters and process of operation thereof



Feb. 1, 1966 R. WATKINS 3,233,097

RAILROAD SWITCH HEATERS AND PROCESS OF OPERATION THEREOF Filed March 5,1964 5 SheetsSheet 1 RAY WATKINS INVENTOR.

ATTORNEY Feb. 1, 1966 R. WATKINS 3,2 7

RAILROAD SWITCH HEATERS AND PROCESS OF OPERATION THEREOF Filed March 5,1964 5 Sheets-Sheet 2 F/G5 4. 27 32 26 EEI 25 1 El iqnm I22 RA Y WA TKINS INVENTOR ATTORNEY Feb. 1, 1966 R. WATKINS 3,233,097

RAILROAD SWITCH HEATERS AND PROCESS OF OPERATION THEREOF Filed March 5,1964 5 Sheets-Sheet 3 RAY WA'TK/NS INVENTOR.

ATTORN EY Feb. 1, 1966 R. WATKINS 3,233,097

RAILROAD SWITCH HEATERS AND PROCESS OF OPERATION THEREOF /28s RAYWATKINS \2 9 INVENTOR. 1

ATTORNEY Feb. 1, 1966 WATKINS 3,233,097

RAILROAD SWITCH HEATERS AND PROCESS OF OPERATION THEREOF Filed March 5,1964 F/GB 5 Sheets-Sheet 5 R AY WATKINS INVENTOR.

ATTORNEY United States Patent 3,233,097 RAILRGAD SWITCH HEATERS ANDPROCESS OF GPERATION THEREOF Ray Watkins, 4220 Albert St., Amarillo,Tex. Filed Mar. 5, 1964, Ser. No. 350,150 14 Claims. (Cl. 246428) Thisinvention relates to improvements in apparatuses to keep railroadswitches and rails clear of interference by snow and ice duringinclement cold weather and to improvements in the process of operationthereof. This is a continuation-in-part of my co-pending applicationSerial No. 163,195, filed December 29, 1961, now abandoned.

One object of this invention is to provide railroad switch heaters ofimproved efficiency, capacity, and reliability of operation, and aprocess for their operation.

Another object of this invention is to provide railroad switch heatersof improved ease of installation.

Another object of this invention is to provide railroad switch and railheaters of improved ease, economy, and reliability of maintenance.

Yet another object of this invention is to provide a process for dryingas well as heating railroad switch sections and thereby maintaining suchswitches in operative condition, notwithstanding wet and cold weatherconditions.

Other objects of this invention will become apparent to those skilled inthe art on study of the below specification, of which specification theaccompanying drawings form a part. In describing the invention referencewill be made to the drawings showing preferred embodiments of myinvention. In these drawings, wherein like numbers refer to same partsin all figures:

FIGURE 1 is an overall perspective view of one installation according tothis invention;

FIGURE 2 is a diagrammatic top view of the railroad track and trackheater portion of an installation as in FIGURE 1;

FIGURE 3 is a diagrammatic perspective view of the fluid heatersubassembly portion of the installation shown in FIGURE 1;

FIGURE 4 is an enlarged perspective view of a rail heater element 86, ofthe apparatus of FIGURE 1, according to this invention;

FIGURE 5 is a sectional view taken along plane SA-SB of FIGURE 6;

FIGURE 6 is a vertical sectional view taken along plane 6A-6B of FIGURE2;

FIGURE 7A is an enlarged vertical cross-sectional view of one embodimentof a rail heater element of this invention as viewed along section 7A-7Bof FIGURE 6;

FIGURE 7B is a similar view of another embodiment of this invention;

FIGURE 8 is an overall plan view of an improved embodiment of switchheater according to this invention;

FIGURE 9 is an enlarged view of the portion indicated as 9A-9B-9C-9D inFIGURE .8;

FIGURE 10 is a sectional View along the section 10A- 1013 in FIGURE 8;

FIGURE 11 is a transverse sectional view along the plane 11A-11B ofFIGURE 8;

, "FIGURE 12 is an enlarged view of portion 12A-12B- 12C-12D of FIGURE10; and

FIGURE 13 is an enlarged view similar to FIGURE 12 along the section13A-13B of FIGURE 8.

An installation according to this invention comprises a fluid heatersubassernbly 11, a left rail heating subassem'bly 12, and a right railheating su'bassembly 13. The ends of suba-ssemblies 12 and 13 are firmlyattached to each other, as by welding in place, as below described, inthe 3,2333%? Patented Feb. 1, 1966 field at the switch section ofrailroad track and roadbed to be serviced by the installation, suchsection being genera-11y shown as 14. The ends of the suhassemblies 12and 13 are also similarly attached to the fluid heater subassem'bly 11,as below described.

The fluid heater sub-assembly 11 sits on concrete piers 29 and 21 whichare firmly fixed in and rest on the ground 23 at a location 24, as shownin FIGURE 1, sufficiently distant from the track switch section 14 toavoid any interference with the traflic thereover. Longitudinal girders25 and 26 rest on, and are firmly attached to, said piers as by anchorbolts. These girders are level and firmly attached to and support thehorizontal bottom of a frame housing 27. The frame of said housingsupports side walls 23 and 29, end walls 30 and 31, a roof 32 and afloor 33. The frame pivotally supports each vertical side wall as 28 ona corresponding horizontally extending hinge, as 28A. The housing thusprovides an enclosed interior space 35. Access to the space as foradjustment and maintenance is provided by the pivotal rotation of thevertical side walls about the aforesaid hinges, as 28A.

A source of butane gas 36 supplies a reservoir 37 which feeds a gasburner 39 in a fluid heater 40 in housing 27. The combustion gasesformed by the burner 39 pass by a flue 41 out of the housing 27. TheWalls of the housing 27 are made of steel sheeting in the preferredembodiment and are l-ouvered as shown at 76 and 77; the gas burnerchamber is louvered as shown at 79 for ingress of the air to the burner.

A source of electric power, line 43, which is the same source asactuates the switch mechanism 44, charges an electric battery 45 insidethe space 35. The battery floats on the line 43 and serves for a sourceof energy of operation during temporary failure of the electric powersource. The battery and/or the electric power source drives a variablespeed electric motor 47 connected to a pump 49. Pump 49 drives a liquidheat transfer fluid, 50, of low melting point, as DOWTHERM E (tradernorkof Dow Chemical Co. of Midland, Michigan for O-Dichlorobenzenestabilized for heat transfor use, having a freezing point of -22 C. anda boiling point at 760 mm. Hg pressure absolute of 179.5 C.) in thepreferred embodiment, through sub-assemblies 11, 12, and 13. Such fluidenters pump 49 from reservoir 51 for such fluid and from fluid heaterinlet line 52 and passes from said pump into the coils 55 of the fluidheater 40. There such fluid is brought into effective heat exchange withthe hot combustion gases formed by the gas burner 39. The heated fluidpasses out from the heater 40 by fluid heater discharge line 57.

The operation of pump 49 is controlled from a conventional control box59, which is supported in housing 27 on the frame thereof. The pump is,as below de scribed, actuated by exterior sensing elements 61 and 62 and63. Pressure sensitive elements as 65 and 66, sensitive to the pressureof the heat transfer fluid in the fluid inlet and outlet linesrespectively and connected to indicating instruments 67 and 63respectively, and temperature sensitive elements 71 and 72 in the inletand outlet lines '52 and 57 respectively connected to temperatureindicating instruments therefor, as 73 and 74, are also connected to thecontrol box 59 for purposes as below described.

' The left rail heating sub-assembly 12 comprises a series of like railheater elements as -88. These elements are located between, and slightlyspaced away from, the ties as -99 and below and out of mechanicalcontact with the nearest (left railroad track rail 102 of section 14.Each heater element as 80-88 is located on top of the surface of therailway roadbed 101 although out of direct mechanical contact with suchnearest rail. Each of the ties as 90-99 is spaced from its neighboringties with from 10 to 12 inchesspace therebetween as shown for ties 95,96, and 97 in FIGURE 5. The ties are each about 7 inches high and from 9to 11 inches Wide. The top of each heating element, as shown for element86 in FIGURES and 6, is spaced from the bottom edge, as 106, of eachcorresponding rail, as 102, where such rail passes directly over saidheating element, by a distance, 104, which distance, in the preferredembodiment, is about 2 inches and in the range of 1 to 3 inches.

The discharge line 57 is connected to and feeds the inlet end 103 of therail heater distribution sub-assembly 12. The fluid heater inlet line 52is connected to, and is fed from, the outlet end line 105 of assembly12.

A right rail heating sub-assembly 13 comprises a series of rail heaterelements as 110 to 118. These elements have the same structure aselements 80-88. They rest on top of the railway roadbcd 101 between andslightly spaced away from the ties as 90-99 and below and spaced awayfrom, i.e., out of mechanical contact with, the right hand railroad rail120. As shown in FIGURE 2, the inlet line 121 of sub-assembly 13 isconnected to the inlet end 103 of sub-assembly 12 and outlet line 122 ofsub-assembly 13 is connected to outlet end line 105 of sub-assembly 12.

In the preferred embodiment, the rail heater distribution elements 80-88and 110-118 each comprise, as shown for element 86 in detail, a hot orinlet conduit 125 and cold or outlet conduits 126 and 127 formed ofstandard steel pipe and a pressed steel heat transfer unit 128. The unit128 comprises an inlet conduit 125A of LD. and outlet conduits 126A and127A of /2" ID. A Web member 130 extends from conduit 125A to 126A and aweb member 131 similarly extends from conduit 125A to 127A. Each webmember, as 130, is formed of two plates of 14 guage pressed steel, as132 and 133. Each upper plate, as 132, is generally flat but pressed toform therein a series of upward projections, with downwardly opengrooves, 134, 135, 136, and 137, each of /s" internal radius: each lowerplate as 133 is fiat and welded to the corresponding upper plate nearthe edge of each of these grooves. Thereby a definite channel as 153 and153A is formed on the interior surface of each of these grooves andserves to connect conduit 125A to conduits 126A and 127A. The grooves,as 134, 135, 136, and 137 are spaced apart 6 inches in the preferredembodiment along the entire length of the unit 128, except however atthe central end, 138, a larger inch I.-D. conduit 139 is provided toconnect the ends of conduits 125A and 126A for directing some of theheating fluid along the entire length of the unit 128. A ven-t 140 isprovided at the central end 138 of the conduit 125A to permit venting ofvapor or air during installation of the parts of the system. Such ventis locked or screwed shut after applying suflicient pressure of fluid tothe system to remove unwanted gas and the fluid system is then closed.The channels, as 153, in each groove as 134, 135, 136, and 137 providefor improved heat transfor from the heat transfer fluid 50 inside thepipes and conduits as 125, 125A, 126, and 126A, to the Web as 130 andthe large surface thereof, and thence, to the associated rails as 102;web 131 has a corresponding structure to interconnect conduits 125A and127A. The unit 128 is made of a lower member 142 comprisingcorresponding lower plates 133 and 133A and the lower portion ofconduits 125A, 126A, and 127A, all made of 14 guage pressed steel. Theupper unit 143, also of 14 g-uage pressed steel, is composed of theupper portions of conduits 125A, 126A, 127A and of corresponding upperplates 132 and 132A. The members 14-2 and 143 are joined together alongtheir adjoining edges by continuous welds 144 and 145 to form thecomplete and leakproof conduits 125A, 126A, and 127A. Conduits 125 and125A are joined by welding as are-conduits 126 to 120A and 127 to 127Arespectively. Each of the rail heating elements as 86 are about 9 incheswide and 2 inches in total height (from top of conduit 125A to bottom of126A and 127A) in the preferred embodiment; this allows their use in theusual 10 to 12 inches space between adjacent railroad ties and providesfor placement of these heating elements above the level of the roadbedriprap and spaced from one to three inches below the bottom level of thenearest rail Where such rail passes over said element. This provides anexcellent radiation situation for transfer of heat from the heatingelements as 80-88 and 110-118 to the rails without interfering with theswitch mechanism moving parts, as 129. The heating elements 80-88 and110-118 are out of mechanical contact with the rail; the piping as 121and 122 and 103 and 105 bringing the heating fluid to and from theheating plates is also out of contact with the rails and the ties and issupported on the relative stable railroad track roadbed.

Accordingly, the heating system elements according to this invention aresubjected to a minimum amount of vibration. The welding of the jointsabove described to provide the assembly of the above describedsub-assemblies also prevents leakage of the heat transfer fluid andserves to provide an apparatus and installation which is very sturdilyconstructed and thoroughly able to resist the vibration which occurs inthe operation of the railway track bed while avoiding that occuring inthe railroad rails. The heater, in the preferred embodiment, puts outabout 147,000 B.t.u. per hour and provides for a discharge temperatureof fluid of 225 F. in line 57 at about 15 p.s.i. gauge pressure whilepump 49 has /3 H.'P. and discharges 7 /2 gallons per minute at a 12-foothead. The

series connection of the rail heating elements as 80-88 (inlet of secondelement to outlet of first element, inlet of third element to outlet ofsecond element, etc.) provides that the heating fluid in its hottestcondition, i.e., coming most directly from the heater discharge line 57,passes, in the preferred embodiment, to the bottom of the most criticalzone in the switch section, i.e., zone 150 below the tips 148 and 1 .9of the movable tongues 151, 152 of the switch.

In a preferred embodiment of this invention the rails 102 and 120 arestandard 8 inch high rails spaced inches apart from each other and 3inches wide at their top, and the ties as 96 and 97 are each 9 feetlong, so that there is a two-foot lateral extension of the ties as 90-99beyond the rails 102 and 120.

The plates as 130 and 131 in left hand sub-assembly 12 extend from 2feet to the left of the left rail 102 to within 1 to 2 inches of thecenter of the distance between rails 102 and 120. The plates in theright hand suba and 13, are connected in series across lines 52 and 57as shown in FIGURE 2 for the sub-assembly 12, and web plates, as 130,131, are continuous sheets.

External temperature sensing element 61 is located on tie 100 betweentrack rails 102 and 120 a distance of several ties from the nearestheater plate element as and 110. External thermal sensing element 62 issimilarly located on tie which tie is located a similar distance alongthe track from the other end of sub-assemblies 12 and 13. Suchtemperature sensing elements form a part of sub-assembly 11 and areconnected to control box 59 to cause pump motor 47 to begin operationand heater 39 to heat the fluid 50 in boiler coils 55 when the outsideor ambient temperature falls to a predetermined level-as 35 F. in thepreferred embodiment. An external sensing element 63 is located betweenthe rails 102 and 120 and out of contact with any heater element, as90-98 or -118, and is located on top of a tie as 95 between heaterelements, as shown in FIGURE 2; it cuts off fluid heater 39 when thetemperature of air sensed by said element is above 90 F. Internalsensing elements 71 and '72 incretase the speed of motor 47 and thepump-rate of fluid 5e whenever the temperature of the return fluid inpipe 52 is more than 30 F. lower than in the discharge line 57. A safetyvalve (not shown) cuts off the heater 39 when the pressure in thedischarge line 57 exceeds 50 p.s.i.g. or falls to zero and cuts back theheater slightly when the discharge line pressure is over 25 p.s.i.g.

In operation lines 57, 103, 121, 105, and 122 conduct the heated heattransfer fluid in a closed circuit including the inlet and outlet pipesas 125 and 126 of each of the heater elements as 80-88 and 110-118 andthe fluid heater 40.

Each of the heater elements as 80-88 and 110-118 are located on the topof the railroad roadbed riprap so that the transfer of heat by radiationfrom said elements to the rails thereover will not be diminished byoverlying material. The porous layer of gravel or riprap of the roadbedbelow those plates serves as a heat reservoir for purposes belowdescribed.

In the preferred embodiment the hottest fluid is passed directly to thezone 150, where tips 148 and 149 of the movable tongue or turnout rails151 and 152 of the switch 14 are located. This provides for mosteffectively heating the zone whereat such tips of the tongue or turnoutrails are situated and so avoids any intereference with the properoperation of such movable elements by snow or ice or frost settling onor between such rails. This is particularly important in order to avoidderailment problems which may occur because of the accumulation of snowand ice between such moving parts in this particularly sensitive zone.

The left hand sub-assembly 12 is assembled as a unit in the shop and putin place in the switch section 14. Such sub-assembly extends for 18 tiesin the preferred embodiment. More generally, such sub-assembly (as 12 or13) extends from one (as 90) or two ties past the movable end as 148,149 of the movable tongue or turnout rails 151, 152 of a switch to oneor two ties past the pivots, as 159 and 159 for such turnout rails. Theinstallation of sub-assemblies 12 and 13 of this invention thus providesa pair of rail heating elements as 80-88 and 110-118 between each of theties along the length of track between which the movable portion of theswitch section-Le, turnout rails as 151, 152is located, which iength oftrack is serviced by the installation of this invention rather than theparticular number of heating elements and ties shown diagrammatically inFIGURE 2.

For installation, the apparatus of this invention merely requires movingof enough ballast from the roadbed 101 to insert the heating elementsunder, but out of contact with, one of the rails and thereafter puttingone sub-assembly, such as 12, in place as above shown. This is followedor accompanied by putting the other such assembly, as 13, in place;thereafter the joints between these sub-assemblies at points 154, 155,156, and 157 may be welded together. The sub-assembly 11 is assembled asa unit, i.e., prefabricated in a shop and moved to place on top of thepiers 20 and 21 on the girders 25 and 26. The fluid discharge and fluidinlet pipes 52 and 57 are then joined to the pipes 103 and 105 at joints156 and 157.

The porosity of the ballast forming the roadbed 101 below the heatingelement cooperates with the above discussed structure: it serves, notonly as a reservoir of heated material but also to provide passage forthe melted snow coming from the top of the track as a fluid; the porousballast in roadbed 101 is composed of 1-2 and -%"1% crushed stone(nominal size of square opening, in inches, as in Taggart, Handbook ofMineral Dressing, J. Wiley 8: Sons, N.Y., 1944, pp. 3-107) in thepreferred embodiment: It acts as a heated volume of material ofsubstantial heat capacity and also provides channels wherethrough thewater resulting from snow melted under the influence of the hightemperature and large surface area of the heating elements as -88 (and-118) may flow below the level of the ties. This provides for rapid andlateral discharge or escape of the snow or ice mejlted by thesub-assemblies 12 and 13 from the roadbed 101 and thus avoids anybuild-up of ice formation as might otherwise interefere with theoperation of the switching element if such ice were allowed toaccumulate below (and thereafter, above) the level of the ties. Thespace 161, 162 between the elements as 86 and the ties as 96 and 97adjacent thereto allows for runoff from the sloped tops of each element,as 86, of water produced from the melted snow. Thereby drainage awayfrom as well as melting action on snow and/or sleet on the ties and allthe surfaces of the rails 102 and and switch parts, e.g., 151, 152, and159, are provided. The temperature of the rail heater element ismaintained by the above described temperature sensing elements andburner and pump controls at a sufficiently high level (225 F.-185 F.) toevaporate whatever water would remain in contact with those elementswhenever the ambient temperature falls to any given temperature, e.g.,35 F. and the. pump is run at such a speed as to permit only apredetermined temperature drop between lines 52 and 57 and therebyprovides for the evaporation of water on and under the track section 14and, thereby, for the removal therefrom after the snow or ice initiallycont-acting same has been melted.

According to this invention the solid angle 166 seen from the section 14(as at 150) of rails 102 and 120 to heater elements as 86 and 116, isabout this provides excellent heat transfer from the physically near (2inches from bottom edge 106 to top of heating element, as 86) heaterelements of the sub-assemblies 12 and 13 to the rails by radiation whilemechanically such rail heater elements as 80-88 and 116-118 are notsubject to direct mechanical vibration from the rails as 102 and 120,and 151 and 152 from trains passing thereover.

Also, by the apparatus of this invention, when the ambient temperaturedrops, as sensed by distant (from sub-assemblies 12 and 13) elements d1or 62, the heater 11 and sub-assemblies 12 and 13 render the entireporous roadbed mass 101 in their vicinity warm and thus establish a heatreservoir in the roadbed 101 in the zone below the switch section 14 tominimize any subsequent accommulation of ice and water in such zone;then, when frost, snow, or sleet subsequently occur, the ice or snowresulting from such weather which is melted has, in the preferredembodiment, a warm porous zone of the roadbed 101 through which todischarge the liquid resulting from melting of such snow and ice orsleet above the level of roadbed 101 by the action of sub-assemblies 11,12, and 13 as above described.

Because the rails as 102 and 120 may get quite cold due to radiation ona cold, clear night, moisture in the atmosphere frequently settles onand forms ice between the rails as 102, 120 and the points 148 and 149of the movable tongue or turnout rails as 151 and 152 of a switch, as14: Such ice interferes with the operation of such switches. Theapparatus of this invention, however, being set to start when theambient air temperature falls to about 35 F., prevents ice forming onsuch structures and from so interfering with the operation of suchswitch. In the preferred embodiment above described, this apparatusprovides a large heat capacity-147,000 Btu. per hour boiler outputforthe 30 foot length of track section 14, serviced by this installationand this apparatus provides for the delivery of substantially all ofsuch heat energy to the rails and also to below the level of the railsto provide channels as 168 in the porous roadbed 101. The water whichresults from the melting of the snow and ice coming to a switch sectionduring inclement cold weather may be removed by such channels to thesides, as 169, of the railway roadbed 101. When the roa'dbed is not soporous, another structure of apparatus within the scope of thisinvention, as below described, provides for discharge of the waterresulting from melting of such ice and/or snow and/ or sleet laterallyof the rails of the section serviced by the installation of thisinvention.

During an experiment when there was weather of F. to 3 F. for 12 hoursand 35 mph. winds there was only a 22 F. drop from the discharge line 57to inlet line 52 and using the installation of the above describedpreferred embodiment for the 18 ties in the 30-foot long switch section14, sub-assemblies 12 and 13 extending 9 inches length-wise beyond theends of the movable turnout rails as 151 and 152, such section waspreserved totally without any ice formation thereon notwithstanding thedeposit in the immediate vicinity of said track section of 3 inches ofsnow. Also, during a inch fall of snow in 3 hours at an averagetemperature of 4 F. the above section was maintained free of anyaccumulation of ice and moisture. The snow was observed to be melted anddischarged from the tracks and ties and units as 128 substantially assoon as such snow contacted same.

This invention also includes the process above described of maintaininga railroad track and switch section (as 14) free of encumbrance by iceand snow, said process comprising the steps of heating said movablerails and portions of the fixed rails adjacent thereto by the transferof heat thereto by radiation from heated elements out of mechanicalcontact with said rails and located below said rails and between saidties, said elements providing about 900 sq. inches of surface upwardlydirected and located below each 20 inches of length of said pair ofrails, While said elements are concurrently heating the porous roadbedbelow said heating elements and so distribute up to about 5,000 B.t.u.per hour per foot of length of track as needed from said heatingelements to said track rails and roadbed therebelow to discharge meltedsnow and ice substantially (2 feet in the preferred embodiment, as theunits as 86 extend as far laterally of the rails thereabove as do theties, as 96, 97) laterally of said rails.

As above described, the heating elements are heated by fluid at about225 F. so that, in the preferred embodiment and procedure, said heatingelement surfaces are maintained above or at the boiling temperature ofwater. This effects and expedites evaporation of water from the ties andrails above said heating elements, from the heating elements, and 'fromthe interstices of the porous roadbed below said heating elements and soavoids accumulations of moisture on said surfaces as might subsequentlysolidify and interfere with the operation of the switch.

VVhile according to the preferred embodiment of this invention abovedescribed, a porous roadbed is used, it is within the scope of thisinvention that the apparatus consisting of subassemblies 11 (whichincludes the associated sensing elements as 411, 62, and 63) 12, and 13be used with a relatively non-porous roadbed such as one made of tightlypacked sand. For use in such circumstance, the upper surfaces as 130 and131 of unit 128 in each heating element as 80-88 and 110-118 aremodified from as above described in reference to the embodiment shown inFIGURE 7A to a structure as shown for web plate elements 180 and 181 inheating element 85 shown in FIGURE 5 and FIGURE 7B. Each upper surface132 and 132A of web plate elements 180 and 181 is fiat rather thanribbed by upwardly projecting grooves as 134, 135, 136, and 137 as shownfor element 86. In the embodiment shown as item 85 of FIGURES 5 and 7B,a series of downwardly projecting grooved extensions as 184(corresponding to mirror images of items as 134) and 184A (correspondingto mirror images of items as 134A) each with an upwardly open channel orgroove 185 (in 184) and 185A (in 184A) respectively are provided in thelower web plates 133 and 1%3A of such modified unit 128 in lieu of theabove described component of the lower web plates (133 and 133A) of unit128 so that downwardly projecting grooves and passages (functioninggenerally as 153 and 153A provided in upper plate 132) are then providedby plates 180 and 131 and chambers 185 and 185A predominantly in thelower web plates. The upper surfaces of web plates 180, and 181 are thenlocated in plates as 160-160 and 162162 respectively as shown in FIGURE7B; planes 1504160 and 161-161 pass through the centers of thecyiindrical conduits 126A and 127A respectively. The sloped position ofthe heating elements as 85 and 116 in FIGURE 6 (which position is alsotypical of the position of similar elements 80-83 and 110113) providesthat the central portion, as 138 of each heating element, as 86 and alsois higher than the lateral portion of each such element (such lateralportion being connected to the inlet and outlet pipes therefor, as 125,126, 127). Each such element, as 35, also passes underneath theassociated rail, as 102, with one to three inches space between saidrail and said element where said element passes directly below saidrail.

This sloped position of the top surfaces of the web plates as 180 and181 provides, in each such heating element, for drainage of waterresulting from the melting of snow and/or ice or sleet thereon anddischarge thereof laterally of the rails (as 102 or 120) associatedtherewith by passage of such Water along the laterally downwardly slopedtroughs formed by the sloped upper flat surface as 130 and conduit 125Aand along the laterally downwardly sloped trough formed by the slopedtop surface of the Web plate 181 and the conduit 127A; elements as 35'extend as far laterally as do elements as 85, namely as far as the tieson either side of such heating element. Otherwise the installation ofsub-assemblies 11, 12, and 13 when used with a non-porous roadbed is thesame above described with a porous roadbed. The elements as 85' may beused with a porous roadbed as well as with a non-porous roadbed.

The units of the apparatus of this invention have been described for aswitch unit 14 of 18 tics length from a first tie, as 90, located pastthe ends of the movable tongue or turnout rails as 151., 1'52 to thelast tie of such section, as 99, located on the other side of the pointsabout which such movable turnout rails pivot, as 159, 159', and thedistance from said first tie to said last tie is 30 feet. Theinstallation and process of this invention are, however, intended to beused where the switch length is shorter (e.g. of 6 to 7 ties and about12 feet length) as well as longer. With such shorter or longer switchesa heater or unit as 40 may be of lesser or greater output in order toprovide, as above described, up to 5,000 Btu. per hour per foot oflength of track, eg about 150,000 Btu. per hour output for a 30-footlong installation and about 60,000 B.t.u. per hour output for a 12-footlong installation with the heating units as 83 and 110-116 or units suchas in subassemblies as 12 and 13 providing about 900 square inches ofsurface (9 inch width X about inches total length) for each 20-inchlength of track (i.e. 20 inches of total length of the pair of trackrails as and 102 and ties therebetween) such heating elements being, asabove described for the preferred embodiment, located close to (from oneto three inches distant where the rails pass above each of the heatingelements) yet spaced away from the rails to be heated by each saidheating element, and said heating elements provided with fluid in thesame manner as above described for the preferred embodiment and at thesame heat intensity-i.e., 225 F, as above described for the preferredembodiment.

While Dowtherm E is described as used in the preferred embodiment, otherheat transfer fluids of low melting point and high boiling point such asethylene glycol 9 (M.P., -l7 C.; B.P., 197 C.) stabilized for heattransfer use in a metal system as herein provided, or air may also beused as fluid 50 herein.

It is also within the scope of this invention that a thermopile actuatedby the heat of burner 39 may be connected to box 59 and battery 45 toprovide the electrical energy required to drive the motor 47 if thesource of electrical energy 43 should fail. Such arrangement providesthat the installation of this invention would be entirelyself-contained, without dependence on outside energy, for long periodsof time in the event of the failure of the electrical energy source 43.Also within the scope of this invention such a thermopile may replacethe source 43.

The temperature-sensing elements 61, 62 and 63 which are eachconventional temperature-sensing instruments, are indicated by thestandard representation for an instrument locally mounted as set out atpage 336 of Eckman, Industrial Instrumentation, John Wiley & Sons, NewYork, 195%), although, specifically, a Model V-l Thermostat of theBerling Instrument Company, South Orange, New Jersey, may be used, theMinneapolis Honeywell Model L4008C Thermostat F.-70 F. range ispreferred; the thermostat is adjusted so that the contacts thereof areclosed when the ambient air temperature descends to 35 F. and remainsclosed at all temperatures therebelow.

The control box 59, shown in the drawings as a square, is a conventionalcontroller well known per se, such as a Honeywell R7087D ResistanceThermometer Controller, and, in the preferred embodiment, a MinneapolisHoney- Well Model RA-816A; the box is set to de-energize the burner whenthe fluid temperature rises above 400 F. and to re-energize the burnerwhen the fluid temperature drops to 360 F.

The gas burner 39 is a conventional burner well known per se; in thepreferred embodiment above described, a Carlin Model 400N-3 pedestalmounted with a I 2CB-10O single-stage fuel unit and a /8 H.P., 120 volt,6O cycle motor. The single-stage fuel unit has a built-in strainer andpressure-regulating valve. The motor has a safety overload valve. Theburner has the usual wire electrode which, in the preferred embodimentis a conventional wire and porcelain electrode assembly, Carlin part No.423 in the preferred embodiment. The strainer is provided in thefluid-circulating system to keep impurities from affecting the pumpoperation. The /8 HP. motor operates a fan.

The pressure-sensitive instrument 65 is a conventionalpressure-sensitive element. In the embodiment of FIG- URES 1-5, aMcDonnell No. 69 fluid cutoff is used.

The temperature-sensitive element '72 also is a conventionaltemperature-sensitive element well known per se; in the embodiment shownin FIGURE 2, a Minneapolis Honeywell T654-A or Mercoid IDA-35 is used,such element is adjusted so that its contacts open when theheat-transfer fluid reaches a temperature of 400 F. and recloses whenthe fluid temperature drops to 360 F. in the preferred embodiment.

The switch heater installation according to the embodiment of myinvention on the track section shown as 214 in FIGURE 8 has the samegeneral structure and components as shown for section 14 abovediscussed, and additionally, has a shield, 201; that shield incooperation with the heating panels provides an insulating and heatingair volume above the ties as well as above the spaces in theroadbedbetween the successive ties, said spaces being usually referred to asthe cribs. The shield is, in the preferred embodiment, made of aheatinsulating material, such as X1-1I1Cll plywood. The switch heatershown in FIGURES 8-13 comprises the fluid heater subassembly 11, theleft rail heating subassembly 12, and the right-hand rail heatingsubassembly 13 as above described. The ends of subassemblies 12 and 13are firmly attached to each other, as by welding in place, as abovedescribed, in the field at the switch section of railroad track androadbed to be serviced by the installation, such section being generallyshown as 2 14. The ends of the subassemblies 12 and 13 are alsosimilarly attached to the fluid heater subassembly 11 by lines 52 and5'7 as above described and actuated by the elements 61 and s2 and 63 asabove described for the apparatus of FIGURE 1.

The particular switch embodiment shown in FIGURE 8 in plan view is a No.20 Turnout Switch described at pages 169 and 170 of the Atchison, Topekaand Santa Fe Railway System Rules-Maintenance of Way and Structures,Operating Department 1960, drawing C.E.S. No. 5890, sheets 1 and 2, andprovided with heating panels and shields according to this invention.

According to the embodiment of this invention as shown in FIGURES 8-13,the shield generally indicated as 201 provided over the ties of therailroad switch section 214 comprises three parallel series ofcontiguous A-inch thick wooden plates supported in whole or in part uponor attached to each of the ties between the track rails and laterally ofthe rails. This shield extends from one heel edge 231, at one side ofthe heel of the switch to a point edge, 232, one tie removed from thecrib in which the control arm for the points 248 and 249 of the switch200 is located. The section 214 comprises switch 200, its ties and thecontrol structure therefor.

The shield 201 comprises a central portion 228, a lefthand lateralportion 2.29, and a right lateral portion 230.

The central portion 228 of shield 2&1 located between the rails 2&2 and221 of switch 2% comprises fixed portions 250-255 and movable portions290-294.

The fixed portions as 250-255 are attached to, and supported on, fixedspacing elements; those spacing elements are attached to theconventional ties of section 214, shown as 265-213, 215-219 and 221-222.The fixed shield portions are each /61 -inch thick, imperforate,horizontal, flat plywood sheets of low thermal conductivity that coverover the central portion of each tie and extend on either side thereofto within 1%. inches of the inner side of the head of each adjacentrail, as 351 and 3522, whichever is nearer. The rails are conventionallyspaced apart 4-feet 8 /2 inches, the maximum Width of the portion 228 is4-feet 5 /2 inches. The top of the plywood sheet is level with thebottom of the head of the rails and spaced away therefrom by a leftcentral air escape space 346 and a right central air escape space 341.The fixed portions 250-255 are each provided with lateral roadmaintenance access openings, as Zed-267, for inspection and maintenanceof spikes and chairs holding the rails and tongues to the ties. Spacingelements as 281-288 are built up from nominal 2" x 4" lumber to a 3-inchx 7-inch horizontal section size with the 7-inch side parallel to thelength of rails 202 and 221 These elements are bolted to the tietherebelow (or the gage plate in case of ties 218 and 219) to providevertical support for the horizontal shield portion thereabove and tospace such horizontal portion with the top thereof at the level of thebottom of the heads of the rails supported on such tie. Elements 281-28? also serve to fix the shield so that the lateral edge thereof willbe spaced sufficiently far enough across the air escape space 3 th or341 from the nearest rail or tongue point to avoid contact with arailway car wheel flange riding on such rail structure. The distanceacross the spaces 340 and 341 in the preferred embodiment hereindiscussed is 1 /2 inches each.

The movable shield portions 290-294 are each formed of flat, horizontalplywood the same as used for the portions 239-255. The portions 290-294are each, as shown for portion 290 in FIGURE 11, centrally of its lengthlocated and drawn downward by a /2-inch diameter steel I-bolt, as 295;the J-bolt is supported at its lower end on the movable control rod 297,which rod is actuated by the conventional switch mechanism as 44. Theheel and point ends of the movable portion 290 are slidably sup- 1 1ported on the top surface of the adjacent fixed supports 283, 284, 285and 236. The bottom of each of the movable shield portions, as 299, andthe top of the stationary supports therefor, (as 283-286 for 2%) aregreased to facilitate ready motion of the slidable portions past suchsupport.

The lateral shield portions 229 and 230 are each formed of animperforate lateral portion, as 300 in the right hand portion formed, ina preferred embodiment, of 8-inch wide, A.-inch thick plywood and a16-inch wide sloped, central portion as 3ii2', similar to 302 abovedescribed but on the left hand portion 229 also formed of -inchimperforate plywood sheet, which extends from the inner edge 304 ofportion 304) to within /2-inch of the head of the adjacent rail and withthe bottom surface of the portion 3112 at the level of the bottom of thehead of the adjacent rail leaving a right lateral air escape space 34-3between rail 220 and shield portion 231 The portion 3&2 is also held inplace by a support 3% fixed to the tie and may rest on a rail brace, as3&8. The bolt 31% fixes portion 302 to its support as 3% and tie as 216,and bolt 312 ties the plate as 3% to its tie as 216. The relations ofthe plates to the tie are the same in other ties except where gageplates are used, as on ties 218 and are. There the steel gage plate 315is bolted to tie 219 and the panel 392 is provided with a hole to clearand adjust the nut 31"] of the chair or brace 319 for the rail 202.

The supports 281, 282, etc., are so spaced and located as to providethat the hot air generated by the heating panels of subassemblies 12 and13, such as 81-88, will travel from one crib space, as 321, to the othercrib space, as 322, over the intervening tie, as 2118 and equalize thetemperatures thereof.

The A-inch, S-ply plywood, outside grade, used for the shield 2&1 andits component panels provides a small heat transfer as well aselectrical insulating element between the rails. The heat insulating andimperforate characteristics of shield 2M provide that the heat generatedby the heating panels of subassemblies 12 and 13 provides a stack effectand convection currents of heated air which cause a drying as well asheating current of air to pass through the air escape spaces past theheads of the adjacent rails, which rails are thereby kept warm as wellas dry. Such convection currents also pass through the intersticesbetween the rails at the points of said rails and serve to keep themdry.

The portions 229 and 230 of the shield on the outside, or lateral,portions of the rails are supported on the ties therefor and, as abovedescribed for the central porportions, provide for passage of the hotair developed by the panels of subassemblies 11, 12 and 13 from one cribspace to the other laterally of the rails. There is a /2- inch leftlateral air escape space 342 between the central portion of the sloped,left lateral panel, 229, and the head of the adjacent rail 292. Incooperation with the subassemblies 11, 12 and 13 a heating and dryingcurrent of air passes through that narrow air escape zone as well ascorresponding zone 343 to the right of rail 22d. The space between eachtie and the central portion as 392 provides for passage of hot air fromone crib space to the other over the lateral portion of such tie, aswell as permitting a heating action by convection as well as radiation.The porous roadbed permits air to enter the space above the vicinity ofthe heating panels from the sides of the shield (and ties) and, afterbeing heated, to rise to the air escape spaces. The shield directs theflow of heated air to the zones at which such heated air mostefficiently dries the rails where needed.

The shield 201 in the preferred embodiment extends longitudinally fromthe two ties to the rear of the pivots 259 and 259' to two ties beyondthe tips 248 and 249 of the turnout rails 351 and 352. The functionstructure and operation of the control elements 61, 62 and 63 and of thefluid heater subassembly and components in its housing 27 are the sameas above described for the embodiment of FIGURE 1 and the operation ofthose elements are the same as above described for the embodiment ofFIGURE 1. The elements 61 and 62 are located on ties 361 and 362 eachfive ties away from the ends of the shield; i.e., element 61 is locatedon tie 361 five ties beyond point edge 232 of shield 2151, and element62 is located five ties beyond heel edge 231 of shield 2-91. In theembodiment of FIGURES 8l3 element 63 is located on tie 2%9 and connectedto subassembly 11 by line 363.

The above structure of shield 291 and subassemblies 11, 12 and 13provides for a roof composed of the shield elements 226, 229 and 230with orifices with definite but limited areas provided for the escape ofthe air heated by the heating panels such as 81-88. With the operationof the heating subassembly 11 actuated by control elements 61, 62 and 63as above described the structure of the embodiment shown in FIGURES 8l3provides a substantial upward flow of hot and dry gas (air). Such heatedair passes upwardly from the heated panels of subassemblies 12 and 13below the central portion 228 of the shield 261 through the left andright central air escape spaces 344 and 341 and from the portions ofsubassemblies 12 and 13 lateral of the rails upwardly through thelateral air escape spaces 342 and 343. Thereby the heated air from theupper surfaces of subassemblies 12 and 13 is directed at and past theheads of the switch rails and tongues. This flow of hot, dry gasprovides for an effective drying action as well as heating action onthose rails and tongues. This drying action prevents damaging effects ofice and/or snow. It is a feature of this invention that the largesurface area of the panels of subassemblies 11 and 12 provides for alarge output of heat as above described to the Zone between the heatingpanels as 86 and the shield portions as 228, 229 and 230 thereabove aswell as to the roadbed below the heating panels. This structure andoperation produces a certain stack effect which is greatly magnified bythat the exit orifices thereof, 3419, 341, 342 and 343 have an area(horizontally measured) substantially smaller than that of the heatingsurface; i.e., the heating surface substantially covers the entirehorizontal area of the roadbed between the ties while the central exitorifices 340 and 341 are only about 1 /2 inches wide between the head ofthe rail and the outside edge of the shield, and spaces 342 and 343 areonly /2-inch wide. This provides for development of definite convectioncurrents whereby warm and dried air continuously passes upward incontact with the head of the rails by convection. Such stream of air hasan upward velocity of at least a quarter of a foot per second and ashigh as four feet per second during operation of the apparatus of FIGURE8 when the ambient temperature is at 0 F.

This relatively low intensity of temperature in the panels ofsubassemblies 12 and 13, i.e., below 400 F., without any additionalfans, produces a substantial drying action on the rails through theconvection action of the air heated by these panels and constrained totravel in a limited zone immediately adjacent the railheads. This dry,warm air stream removes moisture from, as

eil as prevents its collection on such rails and structures. This dryingof the rails by a passage of dry and hot air therepast according to theapparatus and process of this invention is a continued operation whichis efficiently and economically carried out by the apparatuses of thisinvention Without damage to the Wood str cture of the railbed, andwithout violent temperature stresses to the metal parts and at arelatively steady state and is performed without any moving parts.

The orifices provided by the access openings 261267 over the spikes andtie plates provide for a drying and maintaining of those elements in drycondition through these cold and wet spells and thereby avoiding thet-emperature stresses concomitant on low temperatures and alternate wetand dry conditions whereat the coefficient aasaoev .13 of expansionbetween the wood and metal may be dissimilar. Nevertheless, it is withinthe scope of the invention that the pockets 260, 261, 262 and 263 hereinprovided in the embodiment of FIGURE 8 above described for purposes ofinspection may be covered by hinge doors as 345 which are transparent inorder to facilitate the inspection of the items therebelow, as spikes orbolts and allow the ready manipulation of such items as required;although for economic purposes of construction the structure abovedescribed provides a new and useful apparatus per se, the use of hingeddoors over the access spaces provides additional economy and efficiency.

This invention thus includes a process of maintaining railroad tracksection free of encumbrance by ice and snow, (said track comprising apair of rails, ties and a roadbed, said rails being in contact withatmospheric air and supported on said ties, said ties supported on saidroadbed), comprising the steps of continuously sensing the temperatureof the atmospheric air as by elements 61 and 62 at a distance from saidrails of said section and supplying heat to a heat conductive surface asthe panels of subassernblies 12 and 13 and maintaining said surfaces ata temperature between 185 F. and 400 F, supplying said heat at the rateof 5,000 B.t.u. per hour per foot of length of said section by thesubassembly 11. The heating surfaces are below the level of the bottomand top of said rails to provide a stack effect for development ofconvection currents. The heating surfaces provide at least 500 squareinches of upwardly directed surface per foot of length of said section;the body of air under the shield contacts the said heated surface of thepanel and the shield confines said body of heated air above all of theheated panel surfaces except those below the air outlet orifices whichconfine the heated air to pass upwardly only in the /2 to 1 inch wideair outlet orifices adjacent the rails. The heating and convectioncurrents provided serve to pass said heated air in a stream of from /2to 1 /2 inches width upwardly at a speed of /2 to 4 feet per sec nd incontact with and past said rails when the temperature of the atmosphericair at a distance from said section falls below 35 F.

Although, in accordance with the provision of the patent statutes, thisinvention has been described as embodied in concrete form and theprinciple of the invention has been described in the best modes in whichit is now contemplated applying such principle, it will be understoodthat the constructions and operations shown and described are merelyillustrative and that the invention is not limited thereto sincealterations and modifications will readily suggest themselves to personsskilled in the art without departing from the true spirit of theinvention or from the scope of the annexed claims.

I claim:

1. Apparatus for heating a railroad track switch section comprisingrails, ties, and a railbed therebelow, said apparatus comprising (a) asource of heated fluid automatically controlled to discharge heatedfluid, said source comprising in operative connection, a fluid heater, afluid heat transfer medium, a pump for said fluid, and a chamber whereinthe heater heats transfer medium, a temperature sensing element exposedto ambient air temperature and operatively connected to said burner,said temperature sensing element being operatively connected to fluidheater for increasing the rate of heating of said heat transfer fluid insaid fluid heater at a predetermined ambient air temperature range.

(b) railway track heating elements located between and spaced away fromthe ties of said railway track and below and out of cotnact with saidrails, said heating elements each having an inlet chamber running alongthe length thereof and an outlet chamber connected to said inlet chamberand running along said length, said chambers being spaced apart fromeach other, fluid conduit means connecting the outlet of said fluidheater to the inlets of said heating elements, and a thermallyconductive plate firmly connected to said inlet and outlet chambers,said track heating elements covering the major portion of the upwardlydirected area between the ties, and

(c) a railroad railbed underneath each of said heating elements, andsaid temperature sensing element being distant from said source of heatand from said railroad track heating elements.

2. Apparatus as in claim 1 wherein the heating elements have an upwardlydirected surface of above 500 square inches for each foot of track andsaid fluid heater provides 5,000 B.t.u. per hour per each foot of saidtrack to each of said heating elements.

3. Apparatus for heating a railroad track switch sec- .tion comprisingrails, ties, and a railbed therebelow said apparatus comprising (a) asource of heated heat transfer fluid automatically controlled todischarge said fluid above the boiling point of water, said sourcecomprising a gas burner, a source of combustible gas, coils for a heattransfer medium fluid and a chamber wherein combustion gases of saidburner may contact the said coils for and containing said heat transfermedium, a temperature sensing element exposed to ambient .airtemperature and operatively connected to said burner, said temperaturesensing element being operatively connected to said heater forincreasing the combustion rate in said burner and increasing the rate ofheating said heat transfer fluid in said coils,

(b) pairs of railway track heating elements located between and spacedaway from the ties of said railway track and below and out of contactwith said rails, each heating element presenting an upper surface withan upwardly directed surface area of over 200 square inches for eachlinear 16 inches of railway track, said track heating elements having aninlet chamber running the length thereof and an outlet chamber runningthe length thereof, thermally conductive plates firmly connected to eachof said inlet and outlet chambers, said plates extending from laterallyof each of said railway rails to near the center of the space betweensaid railway track rails, the other of said pair of heating elementsextending laterally from the other side of the opposite rail to close tothe center of the distance between said two rails and Within a fewinches of said first heating element, said track heating elements havinga surface which covers from to percentum of the upwardly directed totalarea between the ties-adjacent thereto, conduits connecting said inletchamber and outlet chamber in each heating element and in contact witheach said thermally conductive plate, fluid conduit means connecting theoutlet of said heating coils to the inlet of each of said heatingelements,

(c) a porous railroad railbed underneath each of said heating elementsfor discharge of fluid from the zone above said heating element plate,and

(d) said temperature sensing element being distant from said source ofheat and from said railroad track heating elements.

4. Apparatus as in claim 3 for heating a railroad track switch sectioncomprising movable tongues wherein said heating elements are connectedin series, and the heating elements most directly connected to theoutlet of said source of heat are underneath the tongues of the switchelement.

5. Apparatus as in claim 4 wherein the heating fluid used has a meltingpoint below 5 F. and has a boiling point, at 15 lbs. p.s.i.a. pressurein excess of 212 F.

6. Apparatus as in claim 3 wherein the heating source transfers 100,000B.t.u. per hour to the heating elements, said heating elements havingabove square feet of upwardly directed thermally conductive surfaceexposed to said rails at a level which is a distance of more than 1 inchand less than 6 inches from the bottom of each said rail in said track,for each -foot length of said length of section.

7. Apparatus for heating a railroad track switch section comprisingrails, ties, and railbed therebelow, said apparatus comprising (a) asource of heated fluid automatically controlled to discharge heatedfluid, said source comprising in operative connection, a fluid heater, afluid heat transfer medium, a pump for said fiuid, and a chamber whereinthe heater heats transfer medium, a temperature sensing element exposedto ambient air temperature and operatively connected to said burner,said temperature sensing element being operatively connected to saidfluid heater for increasing the rate of heating of said heat transferfluid in said fluid heater at a predetermined ambient tempenature range,

(b) railway track heating elements located between and spaced away fromthe ties of said railway track and below and out of contact with saidrails, said track heating elements covering the major portion of theupwardly directed area between the ties, an intperforate sheet elementsupported above said heating elements extending over substantially theentire area covered by said heating elements, an elongated opening insaid sheet element, the edges of which run parallel to said rails andslightly spaced away therefrom, and

(c) a railroad railbed underneath each of said heating elements, andsaid temperature sensing element being distant from said source of heatand from said railroad track heating elements.

8. Apparatus as in claim 2 also including at a level below the top ofthe rails and above the portion of said ties between the rails and abovethe track heating elements an imperforate central sheet of low thermalconductivity located between the rails of the track and extending fromone rail to the other with a narrow air outlet orifice between thelateral edges of said sheet and the adjacent rails and an imperforatelaterlal sheet of low thermal conductivity with edges extending alongthe length of each of the outer portion of each of the ties lateral ofeach rail, the heating elements extending lateral of the rails and thelateral sheets extending from above the heating element to an edgesclose to but spaced slightly away from the rails and forming an airoutlet orifice lateral of each rail.

9. Apparatus as in claim 6 also including at a level below the top ofthe rails and above the portion of said ties between the rails and abovethe track heating elements an imperforate central sheet of low thermalconductivity located between the rails of thetrrack and extending fromone rail to the other with a narrow air outlet orifice between thelateral edges of said sheet and the adjacent rails and imperforatelateral sheets of low thermal conductivity located over and extendingalong the length of each of the outer portion of each of the tieslateral of each rail, the heating elements extending lateral of therails and the lateral sheets extending from a lateral edge thereof abovea lateral portion of the heating element to an inner edge close to butspaced slightly away from the rails and there forming an air outletorifice lateral of each rail, an air inlet orifice at the lateral edgeof said lateral sheets opening to the upper surface of said trackheating elements and to said narrow air outlet orifices between thelateral sheet and said rails and said spaces between said central sheetand said rails, said air outlet orifices being higher than said inletorifice.

10. Process of maintaining a railroad track section free of encumbranceby ice and snow, said track comprising a pair of rails, ties and aroadbed, said r ails being in contact with atmospheric air and supportedon said ties, said ties supported on said roadbed, said processcomprising the steps of continuously sensing the temperature of theatmospheric air at a distance from said rails and supplying ltd heat toa heat conductive surface and maintaining said surface at a temperaturebetween 185 F. and 400 F., supplying said heat at the rate of 5,000 Btu.per hour per foot of length of said section, said surface being belowthe level of the top said rails, said surface providing at least 500square inches of upwardly directed surface per foot of length of saidsection, contacting a body of air with said heated surface, confiningsaid body of heated air above the major portion of said heated surfaceand passing said heated air in a stream of from /2 to 1 /2 inches widthupwardly in contact with and past said rails when the temperature of theatmospheric air at a distance from said section falls below 35 F.

11. Process of maintaining a railroad switch track section free ofencumbrance by ice and snow, said railroad track section comprising apair of fixed and movable rails, ties, and a porous roadbed, said railseach having an inner side surface and an outer side surface, a bottomsurface and a top surface, said bottom surface of each said rail beingsupported on said ties, said ties being spaced apart from each other andsupported on said roadbed and extending laterally of said ties andbetween said rails, said section being in contact with atmospheric air,said process comprising the steps of continuously sensing thetemperature of the atmospheric air at a distance from said railroadtnaclc section and, when the temperature of the atmospheric air at adistance from said section falls below a predetermined temperature,heating a volume of heat transfer fluid at a heat source and cyclingsaid heated fluid from said heat source to substantially equal amountsof upwardly directed area of heat transfer surfaces on the inner andouter sides of said rails and spaced away from said rails, transferringheat from said fluid to said heat transfer surfaces by conduction andmaintaining said heat transfer surfaces at a predetermined elevatedtemperature range between 185 F. and 400 F. and transferring heat to theinner side and outer side surfaces of said rails from said heatedsurfaces by convection and radiation and returning said heat transferfluid from said surfaces to said heat source and blocking upward passageof warmed air from below said heated surfaces between said ties over themajor and central portion of the upwardly directed area between adjacentties and heating the roadbed below the rails and providing warmedchannels therein for passage of water therethrough.

12. Process as in claim 11 wherein snow falls on said section and theheated surfaces occupy to percent of the upwardly directed area betweenthe adjacent ties and the temperature of the heated surfaces ismaintained at 212 to 225 F. and said predetermined temperature is 35 F.and wherein the heated fluid transfers up to 5,000 B.t.u. per hour perfoot of length of said section, said snow is melted to water and saidresultant water is discharged from said roadbed laterally of said railswhereby said roadbed and ties and rails are maintained in dry conditionfree of ice and moisture and the process includes the step ofdiscontinuing the heating of the heat transfer fluid when thetemperature of atmospheric air in contact with said section is apredetermined amount higher than said predetermined temperature.

13. Process of maintaining a railroad track section free of encumbranceby ice and snow, said railroad track section comprising a pair of fixedrails and a pair of movable rails, ties and roadbed, said rails being incontact with atmospheric air and supported on said ties, said tiessupported on said roadbed, said rails each having an inner side surface,an outer side surface, a bottom surface and a top surface, said processcomprising the steps of continuously sensing the temperature of theatmospheric air at a distance from said section and, when thetemperature of said atmospheric air at said distance from said sectionfalls to a predetermined level, supplying heat at a fluid heating Zoneto a heat transfer medium and transferring said heated heat transfermedium to substantially equal amounts of upwardly directed areas of heattransfer surfaces on the inner and outer sides of said rails, heatingsaid surfaces by said medium and maintaining said heat tnansfer surfacesat a temperature range between 185 F. and 400 F., transferring heat toboth inner and outer sides of said rails by radiation and contacting airwith said heated surfaces and thereby heating said air, confining saidheated air to prevent free upward passage thereof from between the railsand laterally thereof above the major portion of said heated surfacesfor passing said heated air upwardly from said heated surfaces only innarrow streams on both sides of said rails, each said narrow streambeing in contact with and elongated parallel to a side surface of one ofsaid rails and said process also comprising the step of discontinuingthe supply of heat to the heat transfer medium when the temperature ofair at said distance reaches a predetermined value higher than saidfirst predetermined temperature.

14. Process as in claim 13 wherein when snow is falling toward saidsection and said heat transfer fluid moves in a closed cycle from saidfluid heating zone to said heat transfer surfaces and back to saidheating zone, the predetermined level of the temperature of saidatmospheric air at said distance from said section is F., said upwardlyflowing streams of heated air have a range of width of one half to oneand one half inches and the heat source transfers up to 5,000 B.t.u. perhour per foot of length of said section to said fluid and the heatedsurfaces provide upward of 500 square inches of upwardly directedheating surface per foot of track length arrayed over the central to ofthe upwardly directed area between adjacent ties whereby said ties andrails are maintained in dry condition.

References Cited by the Examiner UNITED STATES PATENTS 834,439 10/1906Young 246-428 2,815,747 12/ 1957 Greenfield 246-428 X OTHER REFERENCESRailway Age Gazette, volume 48, pages 1199, 1200, May 13, 1910.

ARTHUR L. LA POINT, Primary Examiner.

LEO QUACKENBUSH, Examiner.

1. APPARATUS FOR HEATING A RAILROAD TRACK SWITCH SECTION COMPRISINGRAILS, TIES, AND A RAILBED THEREBELOW, SAID APPARATUS COMPRISING (A) ASOURCE OF HEATED FLUID AUTOMATICALLY CONTROLLED TO DISCHARGE HEATEDFLUID, SAID SOURCE COMPRISING IN OPERATIVE CONNECTION, A FLUID HEATER, AFLUID HEAT TRANSFER MEDIUM, A PUMP FOR SAID FLUID, AND A CHAMBER WHEREINTHE HEATER HEATS TRANSFER MEDIUM, A TEMPERATURE SENSING ELEMENT EXPOSEDTO AMBIENT AIR TEMPERATURE AND OPERATIVELY CONNECTED TO SAID BURNER,SAID TEMPERATURE SENSING ELEMENT BEING OPERATIVELY CONNECTED TO FLUIDHEATER FOR INCREASING THE RATE OF HEATING OF SAID HEAT TRANSFER FLUID INSAID FLUID HEATER AT A PREDETERMINED AMBIENT AIR TEMPERATURE RANGE. (B)RAILWAY TRACK HEATING ELEMENTS LOCATED BETWEEN AND SPACED AWAY FROM THETIES OF SAID RAILWAY TRACK AND BELOW AND OUT OF CONTACT WITH SAID RAILS,SAID HEATING ELEMENTS EACH HAVING AN INLET CHAMBER RUNNING ALONG THELENGTH THEREOF AND AN OUTLET CHAMBER CONNECTED TO SAID INLET CHAMBER ANDRUNNING ALONG SAID LENGTH, SAID CHAMBERS BEING SPACED APART FROM EACHOTHER, FLUID CONDUIT MEANS CONNECTING THE OUTLET OF SAID FLUID HEATER TOTHE INLETS OF SAID HEATING ELEMENTS, AND A THERMALLY CONDUCTIVE PLATEFIRMLY CONNECTED TO SAID INLET AND OUTLET CHAMBERS, SAID TRACK HEATINGELEMENTS COVERING THE MAJOR PORTION OF THE UPWARDLY DIRECTED AREABETWEEN THE TIES, AND (C) A RAILROAD RAILBED UNDERNEATH EACH OF SAIDHEATING ELEMENTS, AND SAID TEMPERATURE SENSING ELEMENT BEING DISTANTFROM SAID SOURCE OF HEAT AND FROM SAID RAILROAD TRACK HEATING ELEMENTS.